The present invention relates to an apparatus for retrieving debris and the like from locations which are accessible through vertical passages. More particularly, the invention relates to an apparatus for retrieving materials from the bottom of a structure such as a street manhole.
During the process of repairing or cleaning street manholes it is not unusual for pieces of the manhole structure, or pieces of the materials used for repair of the manhole structure, to break away and fall to the bottom of the manhole. Such debris must be removed from the manhole after the work has been completed or it can accumulate to obstruct the flow of liquid through the pipe system to which the manhole is connected. In the case of a typical city sanitary or storm sewer system, if obstructions are placed into the flow system it is likely that sewer backup will occur, resulting in damage to systems and property connected to the sewer system. Because of the limited and restricted size of manholes it is difficult for a person to enter into the manhole for cleaning and debris removal purposes. Furthermore, the interior of a manhole is usually poorly lighted making it difficult to locate debris which may have fallen into it.
There is, therefore, a need for some type of device which can facilitate the removal of debris from manholes, particularly after a work project has been completed. It would be advantageous if such a device could be inserted into the manhole before the work project is begun and then removed at the completion of the work project together with all the debris which was created as a result of the work.